FY-4A/AGRI传感器波段平均太阳辐照度计算及不确定性分析

传感器大气顶层波段平均太阳辐照度(Band-Averaged Extraterrestrial Solar Irradiance,BAESI)是表观反射率和星上辐亮度之间转换的重要因子,为了针对FY-4A/AGRI有关通道较为准确地计算这一数值,分别以韩国COMS/GOCI、美国GEOS-16/ABI、日本Himawari-8/9/AHI传感器为例,利用国际上常用的6条太阳光谱曲线与传感器光谱响应函数参与计算BAESI,并与各传感器BAESI标准值进行比较。结果表明,Kurucz计算结果平均绝对误差与均方根误差均最小,是最理想的太阳光谱曲线,此外,Kurucz计算值与各传感器各波段BAESI标准值的最大偏差均小于4.5%,最大偏差百分比及对应波段分别为-2.39%(GOCI-band3)、1.49%(ABI-band6)、4.28%(AHI-08-band6)、4.42%(AHI-09-band6)。因此选择Kurucz太阳光谱曲线参与计算FY-4A/AGRI传感器各波段BAESI值,给出相应结果,并分析了计算值的不确定性,解决了将表观反射率转换为辐射亮度的困难。     

The Variability of Spring Sand-Dust Storm Frequency in Northeast Asia from 1980 to 2011

The characteristic distributions of regional sand-dust storm(SDS) weather processes over Northeast Asia from 1980 to 2011 were investigated using the shared WMO surface station meteorological data,atmospheric sounding data,China high density weather data,NCEP/NCAR reanalysis data,as well as the archived original weather maps of China.The concentration-weighted trajectory(CWT) method was used to calculate the SDS frequency from the discrete station data and to track the large-scale regional SDS weather processes in Northeast Asia.A spline trend analysis method was employed to investigate the variability of the SDS weather systems.The results show that during 1980-2011,the SDS weather processes exhibit both a historical persistence and abrupt transitions with an approximate 10-yr high-low occurrence oscillation.Through composite analysis of atmospheric circulation during high and low SDS years,it is found that the SDS occurrences are closely related to the anomalies of arctic vortex and midlatitude westerly,and the circulation patterns around the Lake Baikal.During the high frequency years,the meridianal flows in the upper and mid troposphere above the high SDS corridor in East Asia(from the Lake Balkhash along Northwest and North China,Korean Peninsula,and Japan Islands) are apparently stronger than the meridianal flows during the low SDS frequency years,favoring the development and transport of SDSs in the midlatitude regions.     

Regional Climate Effects of Internally and Externally Mixed Aerosols over China

A regional climate model is employed to simulate the aerosols(dust,sulfate,black carbon,and organic carbon) and their direct effect on the climate over China.The emphasis is on the direct radiative forcing due to the change in mixing state of aerosols.The results show that direct radiative forcing is significantly different between externally and internally mixed aerosols.At the top of the atmosphere(TOA),the radiative forcing of externally mixed aerosols is larger than that of internally mixed ones,especially in the Tarim desert region where the difference is about 0.7 W m 2.At the surface,however,the situation becomes opposite,especially in the Sichuan basin where the difference is about-1.4 W m 2.Nonetheless,either externally or internally mixed aerosols in China can result in a significant cooling effect,except for the warming in South China in winter and the slight warming in North China in February.The cooling effect induced by externally mixed aerosols is weaker than that induced by internally mixed aerosols,and this is more obvious in spring and winter than in summer and autumn.In spring and summer,the inhibiting effect of externally mixed aerosols on precipitation is less than that of internally mixed aerosols,whereas in autumn and winter the difference is not obvious.     

甘肃省县域经济发展水平空间差异评价

运用<省级主体功能区划分技术规程>中经济发展水平指标的计算方法,以GDP增长率和人均GDP计算出甘肃省1998-2007年各县区的经济发展水平,将其划分为经济发展水平高值区域、较高值区域、中值区域、较低值区域和低值区域,并对近10 a来经济发展时空差异分两个阶段进行了评价.结果表明,甘肃省县域经济发展水平的时空差异十分...     

东南极中山站附近湖冰与固定冰热力学过程比较

2006年对东南极中山站附近湖冰和固定冰的热力学过程进行了系统观测.基于观测数据比较湖冰和固定冰热力学生消过程;分析湖冰和固定冰温度对气温变化的响应规律;计算不同深度层湖冰和固定冰的垂向热传导通量.结果表明:观测的湖泊和海岸区均在2月底至3月初形成连续冰层;湖冰9月底至10月初达到最大冰厚,早于固定冰1-2个月,湖冰最...     

顾及语义差异的基础地理信息客户数据库更新实施模型

客户数据库更新就是利用新版基础地理数据库中更新变化的要素信息,对客户数据库进行相应的级联更新,以使其具有良好现势性的过程。现有研究大多侧重于基础地理数据库更新信息的分发与提供,而没有充分考虑语义差异环境下如何高效实施客户数据库更新的具体问题。针对此,该文概括了基础地理数据库与其客户数据库之间潜在的各种语义差异;从实施效率、数据完备性、一致性、正确性等方面,分析描述了语义差异给更新实施过程带来的不利影响;最后依据语义映射和转换理论,提出了由语义匹配、变化提取、更新集成3种基本操作组成的更新实施模型,并阐述了3种基本操作的执行策略和关键环节。     

基于改进型逆推法和模糊评价法的暴雨服务效益评估

对2010—2022年江西省70次暴雨过程开展了气象服务效益评估,在充分考虑政府组织决策水平、部门联防联动、公众参与及气象服务水平等影响的情况下,加入赋权系数,结合隶属度函数构建重要因子矩阵,基于改进的逆推法和模糊综合评价法建立了江西省暴雨灾害气象服务效益评估模型,实现了江西省暴雨灾害气象服务效益定量化评估。结果表明,2010—2022年江西省暴雨灾害直接经济损失和气象服务效益均有逐渐增长的趋势,不可避免损失因子为0.17—0.50,气象服务效益占经济总损失的25%—45%。暴雨灾害直接经济损失和气象服务效益相关性较高,表明气象服务在防灾减灾工作中起重要作用。     

退耕精确监测及其在辅助决策中的应用研究

退耕还林是党和政府为改善我国西部地区脆弱的生态环境而实施的一项重大工程，投入大，周期长。各级政府、党政领导人都很关注退耕后的实际成效。本文结合林业部门的具体退耕工作流程，介绍了对退耕还林工作进行精确监测的方法，提出了与具体退耕业务相结合的辅助决策应用、系统维护和数据更新模式．讨论了实现退耕精确监测的方法以及在政府辅助决策实际应用过程中的问题。     

周期和振幅相结合检测地震方法研究

分析了单纯用地震波振幅作为报警阈值的缺点,通过数字地震仪与模拟地震仪报警机制的对比,提出用检测周期和振幅相结合的方法来实现地震报警。     

Crystals and fabrics analysis of an Arctic thermal growth multi-year ice sample

One of sea ice core samples was taken from Arctic by the First Chinese National Arctic Research Expedition Team in 1999. 20 vertical and 2 horizontal ice sections were cut out of the ice core sample 2.22 m in length, which covered the ice sheet from surface to bottom except losses for during sampling and section cutting. From the observation and analysis of the fabrics and crystals along the depth of the ice core sample, followings were found. Whole ice sheet consists of columnar, refrozen clastic pieces, granular, columnar, refrozen clastic pieces, granular, columnar and refrozen clastic pieces. This indicates that the ice core sample was 3-year old, and the ice sheet surface thawed and the melt water flowed into ice sheet during summer. Hence, the annual energy balance in Arctic can be determined by the ice sheet surface thawing in summer, and bottom growth in winter. The thickness of the ice sheet is kept constantly at a certain position based on the corresponding climate and ocean conditions; A new